Watch balance spring testing device and crystal microphone therefor



G. T. KUWADA WATCH BALANCE SPRING TESTING DEVICE Dec. 4, 1956 ANDCRYSTAL MICROPHONE THEREFOR 2 Sheets-Sheet 1 Filed March 12, 1954INVENTOR. Gear ellhuwaa'a,

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Dec. 4, 1956 G. T. KUWADA WATCH BALANCE SPRING TESTING DEVICE ANDCRrYSTAL MICROPHONE THEREFOR 2 Sheets-Sheet 2 Filed March 12, 1954INVENTOR. I @eolyeZ/lflwada,

ATTORNfY- WATCH BALANCE SPRING TESTING DEVICE AND CRYSTAL MICROPHONETHEREFOR George T. Kuwada, New York, N. Y.

Application March 12, 1954, Serial No. 415,780

Claims. (Cl. 736) This invention relates to a watch balance springtesting device and more particularly to a crystal microphone arrangementtherefor.

This invention is an improvement upon the invention described in mycopending application, Serial No. 386,- 192, filed October 15, 1953 fora Watch Balance Spring Testing Device.

It is an object of the present invention to provide a sensitive andsatisfactory crystal microphone arrangement which will be effective,operable and eificient in use within the watch balance spring testingdevice disclosed in the above mentioned application.

It is another object of the invention to provide a crystal microphonearrangement for the watch balancing spring testing device which is inthe form of a unit assembly easily secured to the underside of the soundbox of the above testing device and wherein its pick up finger isprojected through the supporting plate and will have direct contact withthe watch as it is retained between the slide jaw assemblies and whereinthe crystal will be rigidly held and supported through engagement withthe finger post and the wire terminals in such a manner that it may notwork loose or be easily destroyed.

Objects of the invention are to provide a crystal microphone arrangementfor a watch balancing spring testing device which is of simpleconstruction, inexpensive to manufacture, has a minimum number of parts,compact and consumes little space, durable and will have long life, easyto adjust and efficient in operation.

For other objects and a better understanding of the invention, referencemay be had to the following detailed description taken in connectionwith the accompanying drawing, in which:

Figure l is a top plan view of the testing device showing the watchretaining slide jaws between which the watch is placed to effect thetesting operation and with the finger of the microphone arrangementbeing extended into a position to rest against the watch when retainedby the jaws;

Fig. 2 is a fragmentary vertical sectional view taken on line 2-2 ofFig. 1 and looking in full elevation upon the crystal microphonearrangement;

Fig. 3 is a transverse vertical sectional view taken on line 33 of Fig.1, and looking in full elevation upon the rear end of the crystalmicrophone arrangement;

Fig. 4 is an enlarged bottom plan view of the testing device with thebottom plate removed and looking in plan upon the bottom of the crystalarrangement and upon the elongated sound box to which the crystalarrangement is attached;

Fig. 5 is a perspective view of the crystal arrangement removed from thetesting device;

Fig. 6 is a perspective view of one of the terminal structures of thearrangement;

Fig. 7 is a fragmentary perspective view of another of the terminalstructures of the arrangement.

Referring now to the figures, 15 represents a round hollow metal soundbox or base having a bottom plate 16 fixed thereto by fastening screws17 with a cushioning 2,772,563 Patented Dec. 4, 1956 gasket 18 disposedbetween the plate and the bottom edge of the base 15.

The base has a large thick flange 19 from'which extends a lateralprojection 20 having an opening 21 therein for receiving a supportingpost 22 that can be rotated within the opening 21 so that its supportingarm 23 carrying center pin assembly 24 may be swung laterally. Thevertical post 22 is secured in its adjusted position by a clamp screw25. It is held against vertical displacement from the projection 20 by awasher 26 and a fastening screw 27 secured to the lower end of the post22.

On the top of the flange 19 there is secured a circular plate 28 bymeans of fastening screws 29. This plate 28 has an elongateddiametrically extending slot 30 in which are adjusted opposing slide jawassemblies 31 and 32 adapted to receive a watch 33 and retain the samefor the purpose of a balance spring 34 being installed therein. Jawfingers 35 and 36 will grip the end of the spring, and the end of thespring will be worked through the jaw fingers to measure and determinethe proper length of the balance spring that is being tested with thepresent testing device taken in connection with a time graph recordingdevice, all in the manner as shown and described in the above mentionedapplication. The fingers 35 and 36 are carried on a slide 37 forming apart of the center pin assembly 24.

The slide jaws 31 and 32 are respectively adjusted by diametricallyopposed adjusting screws 38 and 39 respectively threaded in therespective slide jaw assemblies 31 and 32 in the sound box structure 46.The slide jaw assemblies 31 and 32 are guided on the top surface of theplate 28 by guideway members 40 and 41, respectively held upon the plate28 by fastening screws 42 and 43. The inner ends of the adjusting screws38 and 39 are joined together by a pin projection 44 on the screw 39that enters an opening in the end of the screw 38. A stop washer 45 iscarried on the pin projection 44 and is retained between the ends of thescrews to prevent the slide jaw assemblies from engaging the respectiveopposite screws. These screws engage with depend ing portions of theslide jaws to adjust the slide jaws to clamping or unclamping positions.

Depending from the plate 28 under the slot 30 is a depending innerelongated sound box structure 46 held in place on the underside of theplate 28 by fastening screws 47. The adjusting screws 38 and 39 extendthrough the ends of this box 46 and are respectively held againstoutward displacement from the box and from the base 15 by washer and pinmeans 48.

Fastened to this inner elongated sound box 46 and upon the bottom sidethereof is the crystal microphone arrangement indicated generally at 50,Fig. 5, and embodying the features of the present invention. Thisarrangement 50 has a U-shaped supporting bracket 51 that is secured tothe underface of the box 46 by fastening screws 52 and 53. This brackethas depending legs 54 and 55 between which a T-shaped pivot arm 56extends and into which there extends respectively from the pivot armpivot pins 57 and 58.

On the end of the pivot arm 56 is a round enlargement 59 that carries apost 60 from which extends an upwardly and rearwardly bent finger 61.The supporting plate 28 has a hole 62 through which this finger extendsand the guideway member 40 has a slot 63 in registry with the hole 62and directed inwardly toward the underside of the watch. The upper endof the finger 61 will engage the underside of the watch to pick up anyvibration therefrom resulting from the operation of the watch movement33. The openings 62 and 63 are sufficiently large to permit a full swingamplitude of the finger 61 and so that the vibrations thereof will notbe damped against the body of the device.

To retain the finger 61 against the watch is a bowed spring 64 having abent end 65 extending and anchored to the underside of the supportingplate 28 and a bent end 66 extending into the top of the pivot support56. The lower side of the spring 64 rests against the rear end of thepivot support 56 rearwardly of the pivot connection of the support 56with the depending leg portions 54 and 55 of the bracket 51. This spring64 will tend to keep the pivot support tilted in the manner's'o that thefinger 61 will be held tightly against the underside of the watch Works.

An upstanding stop pin 67 is mounted on the pivot arm support 56 tolimit the upward movement of the finger 61 through the openings 62 and63. This stop pin 67 will engage with the underface of the elongatedsound box 46 and will limit the upward movement of the finger 61. Thewatch upon being placed over the finger will depress the pivot supportagainst the action of the bowed spring 64 and cause the stop pin 67 tobe dropped below the underface of the sound box 4-6. The post 60 on theend of the pivot support arm 56 is recessed on one side as indicated at63, Fig. 5, and within this recess there is supported one corner of asquare shaped crystal 69 that extends rearwardly over the support 56 toa location just forwardly of the stop pin 67. This crystal may be of anyvariety such as to pick up vibrations delivered by the finger 61 to thepost 6!) in a manner to be excited and to alter the passage of electriccurrent passing therethrough. One crystal is known as Rochelle salt butit will be apparent that other crystals may be used for this purpose.

A terminal strip 70 extends from the top surface of the crystal 69, overone side edge, and is connected to a depending projection '71 on theterminal bracket 72 secured to the underside of the enlargement 59 onthe forward end of the pivot support 56, Fig. 7. A terminal strip 73 isconnected to the underface of the crystal 69 and extends rearwardly forengagement with the terminal bracket "74 that has top and bottommounting lips 76 and 77 that seat in one side of a U-shaped insulatingblock 78 that is carried by a portion of the pivot supporting armextending between the bracket arms 54 and 55 in the manner as clearlyshown in Figs. 2 and 5. A current supply wire 7% is connected to aforwardly extending sleeve projection 80 on the'bracket '74. This wireis insulated and extends outwardly through the side of the box 15 asindicated at 81, and as shown in the prior application has a terminalplug by which it can be connected to a time graph recorder having a tapeon which the vibrations of the watch are recorded.

Also, extending between the terminal brackets 72 and 74 in parallelcircuit relationship with the crystal 69 is a small resistor 82. Theforward end of the resistor is connected to a laterally extendingprojection 33 of the bracket'72 and the rear end of the resistor isconnected to a laterally extending projection 84 of the terminal bracket74, Electric current is supplied through the wire '79 and will enter theterminal bracket 74 and be delivered through the crystal and theresistor to terminal bracket 72. Terminal bracket 72 is mounted on thepivot support arm 56 and will conduct current to the pivot support arm56 and to the spring 64 that may serve as a ground wire for groundingthe current into the testing device.

It should now be apparent that there has been provided a simple andeffective crystal microphone arrangement adapted for assembly within thebalance spring testing device shown in the above mentioned patentapplication and which includes a bracket for the mounting of the same tothe underside of the supporting plate of the device and a sensitivefinger that extends upwardly through openings in the main supportingplate and in the guideway member for engagement with the underside ofWatch works while the watch works are being retained by the slide jawassemblies 31 and 32. The vibrations are picked up from the watch andare delivered to the crystal 69 to excite 'the same and to alter thecurrent conditions within an electric current formed by a wire 79.delivering current to a rear terminal bracket v74 through a resistor 82and the crystal 69, to a forward bracket 72 and from this forwardbracket through the pivot support 56, the bowed spring 64 to the body ofthe device. If the proper length of balance spring has been selected, aproper reading will be had upon the time graph recorder. If not, the endof the balance spring 34 will be slid more or less through the fingerclamps 35 and 36 of the center pin assembly 24.

While various changes may be made in the detail construction, it shallbe understood that such changes shall be within the spirit and scope ofthe present invention as defined by the appended claims.

What is claimed is:

i. In combination, a balance spring testing device having a hollow base,a top supporting plate having an elongated sound box connected to theunderside thereof below an elongated opening in said top plate andextending into the hollow base, slide jaw assemblies depending throughthe el-ongated'opening and into the sound box, adjusting screws foradjusting the assemblies toward and away from one another, saidassemblies being adapted to retain and support a watch works, guidewaymembers on the opposite sides of the slide assemblies serving to guidethe movement of the slide jaw assemblies, means extend ing above thebase and overlying the jaw assemblies for supporting one end of abalance spring of a watch while the watch is retained between the jawassemblies, a crystal microphone arrangement comprising a bracketsecured to the underside of the elongated sound box and within thehollow base, a pivot arm support journalled upon the bracket, a springconnected between the pivot arm support and the top plate for urgingupwardly one end of the pivot arm support, finger means extendingupwardly from said pivot arm support through openings in the top plateand the guide way member and adapted to be located in the space betweenthe slide jaw assemblies and to engage with a watch retained there, acrystal member carried by said pivot arm support, terminal bracketssecured to said pivot arm support, one of said brackets being insulatedtherefrom, an electrical resistor and terminal elements extending fromthe crystal and thetresistor to the corresponding terminal bracket andelectrically connecting the same in parallel circuit relationship withone another, a wire connected with one of said terminal brackets fordirecting electric current therethrough.

2. A crystal microphone arrangement adapted for use with a watch balancespring testing device comprising a bracket member adapted to beconnected to the testing device, a pivot arm support pivotally connectedto the bracket member, an upstanding post at one end of the pivotsupport, a finger extending upwardly from the post and adapted to engagewith the watch being tested, front and rear terminal brackets connectedto the pivot support, an insulating member provided on one of thebrackets to insulate the same from the pivot support, a current supplywire connected to the insulated bracket, said upstanding post beingrecessed, a crystal block secured within the recess of the terminalpost, terminal strips extending respectively from the upper and lowersides of the crystal block to the respective terminal brackets, aresistor having terminals connected respectively to the terminalbrackets and spring means on the opposite end of the pivot arm supportadapted for engagement with the pivot arm to normally urge the same inone direction and the finger against the watch works, and said pivotsupport arm having transversely extending axle portions and beinggenerally of T-shape, said bracket member being of inverted U-shape withleg portions depending outwardly of the laterally extending portions ofthe pivot support arm and the laterally extending portions beingjournalled respectively in the respective leg portions,.and a U-shapedinsulating member extending upwardly :and mounting upon the one lateralextending portion of the pivot-arm support and serving to effect theinsulating of the one terminal bracket, the one terminal bracket havinglip engaging portion engaging with one edge of the insulating member,the other terminal bracket being grounded and electrically connected tothe pivot support.

3. A crystal microphone arrangement adapted for use with a watch balancespring testing device comprising a bracket member adapted to beconnected to the testing device, a pivot arm support pivotally connectedto the bracket member, an upstanding post at one end of the pivotsupport, a finger extending upwardly from the post and adapted to engagewith the watch being tested, front and rear terminal brackets connectedto the pivot support, an insulating member provided on one of thebrackets to insulate the same from the pivot support, a current supplywire connected to the insulated bracket, said upstanding post beingrecessed, a crystal block secured within the recess of the terminalpost, terminal strips extending respectively from the upper and lowersides of the crystal block to the respective terminal brackets, aresistor having terminals connected respectively to the terminalbrackets and spring means on the opposite end of the pivot arm supportadapted for engagement with the pivot arm to normally urge the same inone direction and the finger against the watch works, and said pivot armhaving an upstanding post, said finger means including said upstandingpost and a flexible finger, said upstanding post having a recess in theside thereof, said crystal being generally fiat and having one cornerthereof extending into the recess and supported thereby upon the post topick up vibrations imparted by the finger to the post and from the post.

4. A crystal microphone arrangement adapted for use with a watch balancespring testing device comprising a bracket member adapted to beconnected to the testing device, a pivot arm support pivotally connectedto the bracket member, an upstanding post at one end of the pivotsupport, a finger extending upwardly from the post and adapted to engagewith the watch being tested, front and rear terminal brackets connectedto the pivot support, an insulating member provided on one of thebrackets to insulate the same from the pivot support, a current supplywire connected to the insulated bracket, said'upstanding post beingrecessed, a crystal block secured within the recess of the terminalpost, terminal strips extending respectively from the upper and lowersides of the crystal block to the respective terminal brackets, a resistor having terminals connected respectively to the terminal brackets andspring means on the opposite end of the pivot arm support adapted forengagement with the pivot arm to normally urge the same in one directionand the finger against the watch works, and a stop pin for limiting theupward movement of the finger means secured to the upper face of thepivot support arm and having its upper end engageable with the underfaceof the elongated sound box and said spring connected between the topplate and the pivot arm support serving normally to urge the stop pintoward and into engagement with the elongated sound box.

5. A crystal microphone arrangement adapted for use with Watch balancespring testing devices having a top plate, said microphone arrangementcomprising a bracket member adapted to be connected to the testingdevice, a pivot arm support pivotally connected to the bracket member,and upstanding post at one end of the pivot support, a finger extendingupwardly from the post and adapted to engage with the watch beingtested, front and rear terminal brackets connected to the pivot support,and insulating member provided on one of the brackets to insulate thesame upon the pivot support, a current supply Wire connected to theinsulated bracket, said upstanding post being recessed, a crystal blocksecured within the recess of the terminal post, terminal stops extendingrespectively from the and lower sides of the crystal block to therespective terminal brackets, a resistor having terminals connectedrespectively to the terminal brackets and spring means on the oppositeend of the pivot arm to normally urge the same in one direction and thefinger against the watch works, said spring being bowed in shape andhaving an upstanding end projection at one end thereof for engagementwith the top plate of the testing device and 21 depending projection atthe opposite end thereof projecting into said terminal support, saidspring bearing against the rear end of the pivot support and having itslower terminal end connected above the pivot connection of the pivotsupport arm with said bracket, and stop pin means secured to the pivotarm support forwardly of the mounting bracket and engage able with theunderface of the testing device upon which the bracket would be mounted.

References Cited in the file of this patent UNITED STATES PATENTS2,174,692 Dunning Oct. 3, 1939 2,175,021 Gibbs -Q Oct, 3, 1939 2,287,043Kohlhagen 'r'une 23, 1942 2,513,269 Bauer July 4, 1950 2,561,084 Wickham et al. July 17, 1951 2,673,461 Gibbs et al Mar. 30, 1954

